Seismosoft | Earthquake Engineering Solutions

I'm trying to model fluid viscous dampers for a 3 story r/c building TH analysis.
I have used link elements to model the FVD. In F1 I have used "vsc_dmp " with kd=1000000, C=100, a=0.15,0
I take the same global displacement for nodes as in the TH analysis.
When I change the C value I take again the same results for displacements.

Dear user,
On many cases the damping result depends on the correct selection of the damper parameters. In order to help you I would like please to clarify with what units you are woking and to which degree did you change the value of C.
Also please verify the correct connection of the damper with the building members.
Finally one case could be that you have an overall very stiff structure so the dampers do not contribute to the response of the building significantly, you could check the eigenvalues of your building and how do they change with the introduction of the dampers.
Please consider the above recommendations and you can also share your model with us in support@seismosoft.com so we can check if any issue exists.
thank you
Fanis Moschas

Thanks.
I have taken a 3story 1 bay concrete reinforced structure. T1=0.6s, mass=153Tonne, dmax=80mm.
The units are metric, force- KN, dim-m, stress KPa, Acc-m/s2.
the "Cd"is taken 100 and 200 to establish e C-displacement curve.
from Th analysis with Koaceli accelerogram the top displacement are 0.093;-0.097m. even when I put dampers the displacement remain almost the same.
(0.097,-0.095m)
I have send the model to support email.

Dear user,
After receiving your model we ran various tests and discovered that a bug exists in the programm affecting the conversion of units for the initial stiffness variable for the Viscous damper curve. The bug will be corrected in the forthcoming Seismostruct version. Unitl then we suggest that you run your models using the Newton - millimeters units where no problem exists.
We apologise for the inconvenience,
Best regards
Fanis Moschas

The bug will be fixed in the ucoming SeismoStruct v2021 release.
Seismosoft Support